Morning All!!!!

I have blobeye WRX with a few engine mods:

Brand new bottom end with cosworth pistons
Sti Intercooler
Uprated walbro Fuel pump
Decat 2.5 inch straight through exhaust
SFS uprated inlet hose and all other hoses apart from fuel lines

I'm going in for remap in a couple of weeks and I'm trying to gauge the benefits of a decat up pipe?

ANY help is appreciated

 

you can get alot of benifit from the right up pipe. you will get a much qucker spool. speak to harvey on here, i just bought an up pipe from him for my blob wrx and theres a massive difference

 

A standard decatted STI uppipe will work well with your set up. Tne classic and newage ones are he same but the newer the better that way the heat shields will be in good condition.

 

You have had all that lot done and still running the stock TD04 turbo ?

Shaun

 

Speak to harvey, his trick up-pipes are legendary.

 

Yes I'm still running the stock turbo. The rebuild was forced on me by a dodgy map and a blow up. I can't afford a new turbo and injectors at the moment but I'm running low boost for running in at the moment and want to open it out as my run is now complete.

 

Backstreet 'mapper'?

 

Nope, he has a website, all looks legit, advertising, see him at jap shows,etc......but turns out he bought a lead off ebay for a tenner 2 years ago and downloaded some cracked software for nothing and BAM!! he is then a tuner and capable of putting 2 giant holes in my piston within 100 miles of map.....

 

And his name would be................?

 

If anyone wants to ask my personal experience with a given mapper then they can contact me directly but cba with any slander issues on a forum. Anyways, thanks for the advise with the up pipe

 

The airflow through the pre-cat will be enough to spin the small TD04 turbo. If you are on a budget then best to leave it...... Bigger up-pipe might slow down airflow so counter-productive. Harvey up-pipe again not cost-effective for the TD04 as I bet you are going to swap the turbo in the end.

Shaun

 

Shaun
Couldnt disagree more, the cat in the uppipe restricts the gas flow to the turbine, its this gas flow that has the biggest effect on spool. If you are going to even partially decat remove the catted uppipe. Fit either a standard subaru decat uppipe or get one from harvey as previoualy mentioned but if budget is an issue a subaru decat uppipe should cost no more than £40 if in good condition.

 

I agree Archie.

Also, the cats in the up pipe have a tendency to disintegrate and destroy the turbo etc.. once pushed beyond their standard operating parameters.

 

Good point Neil forgot to mention that, when I tweeked the road car I was strongly advised to remove the cat in the uppipe, when you look at it you wonder how any airflow gets through there. I am still on the TD04 in a 55 plate WRX its mapped pretty close to what the Turbo can produce and its plenty for me on a road car makes the car much more responsive and a much better drive. It now produces around 280bhp.